sin^2 60 + cos^2 30 - 5 cos 90 =...

sin^2 60+cos^2 30 - 5cos 90
= (sin60)^2+(cos30)^2 -5(cos90)
= (akar3/2)^2 + (akar3/2)^2-5(0)
= 3/4+3/4
= 6/4
= 3/2

Maaf jika ad kesalahan :)